Give it a try anyway, specially because Drivethru folks will (eventually) update the file.

There some books I consider essential to understand the Dark Ages line, and Bitter Crusade is one of the (the others being Constantinople by Night, Transylvania by Night and Under the Black Cross).

Bitter Crusade update the setting, explaining why (and how) everything changed after 1204, and why the War of Princes gained so much momentum. It covers three years of plotting and treachery, scenarios that can be used as a trilogy or as standalone stories. Also, it brings a healthy amount of information on Italy and Italian Cainites (if you want more, buy Three Pillars).